Wu Yufeng, Tao Ran, Li Bin, Hu Chenwei, Zhang Wei, Yuan Haoran, Gu Jing, Chen Yong
Institute of Circular Economy, Beijing University of Technology, Beijing 100124, PR China; Faculty of Materials and Manufacturing, Beijing University of Technology, Beijing 100124, PR China.
Institute of Circular Economy, Beijing University of Technology, Beijing 100124, PR China; Faculty of Materials and Manufacturing, Beijing University of Technology, Beijing 100124, PR China.
Sci Total Environ. 2024 Feb 20;912:169610. doi: 10.1016/j.scitotenv.2023.169610. Epub 2023 Dec 27.
Pyrolysis is a recycling technology for waste circuit boards (WPCBs) with a wide range of applications. In this research, the brominated epoxy resin (BER) type WPCBs were taken as the research object, and the optimal pyrolysis process parameters were determined. Combined with experiments and density functional theory (DFT) calculations, the pyrolysis gaseous generation pattern and product distribution of BER type WPCBs were analyzed, and the generation mechanism of phenol, bromide and other pyrolysis products was investigated in depth. The results of the study showed that the pyrolysis rate of WPCBs exceeded 95 % under optimal reaction conditions. In the initial phase of the pyrolysis of WPCBs, the BER's CO bonds and a portion of Ph-Br bonds will be broken, leading to the production of intermediates such propylene oxide, bisphenol A, isopropyl alcohol, tetrabromobisphenol A and HBr. Among them, propylene oxide can generate ethylene oxide through free radical reaction. In the second stage, intermediates such as bisphenol A undergo homolytic cleavage and radical addition to form phenols, bromides, alcohols, ketones and other pyrolysis products.
热解是一种适用于废旧电路板（WPCBs）的回收技术，具有广泛的应用。本研究以溴化环氧树脂（BER）型废旧电路板为研究对象，确定了最佳热解工艺参数。结合实验和密度泛函理论（DFT）计算，分析了BER型废旧电路板的热解气体生成模式和产物分布，并深入研究了苯酚、溴化物等热解产物的生成机理。研究结果表明，在最佳反应条件下，废旧电路板的热解率超过95%。在废旧电路板热解的初始阶段，BER的C-O键和一部分Ph-Br键会断裂，生成环氧丙烷、双酚A、异丙醇、四溴双酚A和HBr等中间体。其中，环氧丙烷可通过自由基反应生成环氧乙烷。在第二阶段，双酚A等中间体发生均裂和自由基加成反应，生成苯酚、溴化物、醇类、酮类等热解产物。
